1. Field of the Invention
The present invention relates to technology for non-volatile storage.
2. Description of the Related Art
One example of non-volatile storage uses variable resistance memory elements that may be set to either low or high resistance states, and can remain in that state until subsequently re-set to the initial condition. The variable resistance memory elements are individually connected between two orthogonally extending conductors (typically bit and word lines) where they cross each other in an array. The state of such a memory element is typically changed by proper voltages being placed on the intersecting conductors. These voltages are necessarily also applied to a large number of other unselected memory elements because they are connected along the same conductors as the selected memory elements being programmed or read.
To achieve greater density, memory elements can be part of a three dimensional memory structure. Achieving cost competitive three dimensional memory that consumers will purchase requires that the device operate reliably over many thousands of cycles. This property is referred to as endurance.